Spectrophotofluorometric analysis of 3',4',7-tris[O-(beta-hydroxyethyl)]rutoside in urine

A sensitive procedure was developed for 3',4',7-tris[O(beta-hydroxyethyl)]rutoside (I) in urine. The method is based on the fluoresence behavior of the I-aluminum complex in absolute methanol. This complex has activation and emission wavelengths of 420 and 480 nm, respectively. Optimum conditions for the reaction were investigated. The fluorescence was linear (r = 0.998) in the range of 0.1-4.0 microgram of I/ml. At concentrations below 0.1 microgram/ml, a shift in the emission wavelength was observed. Replicate studies (n = 9) of spiked urine samples, each containing 0.4 microgram of I/ml, showed good precision with a relative standard deviation of 0.009. Overall percent recovery (+/- SEM) from five urine samples was 99.5 +/- 1.34%. Following a single 500-mg po dose of I to individuals, only traces of I were found in the urine. However, beta-glucuronidase treatment of urine resulted in a total cumulative urine excretion of 26.53 mg of I after 78.6 hr.